323 Obstruction

Question 1

Types of intestinal obstruction

Answer 1

mechanical from blockage or functional from intestinal dysmotility

Question 2

most common causes of intestinal obstruction

Answer 2

postoperative adhesions, carcinomatosis, herniation of the abdominal wall

Question 3

most common origin of carcinomatosis

Answer 3

ovary, pancreas, stomach or colon

Question 4

responsible for majority of easly postoperative obstruction

Answer 4

adhesions

Question 5

Most common causes of acute intestinal obstruction

Answer 5

extrinsic, intrinsic diseases and intraluminal abnormalities

Question 6

Examples of extrinsic disease

Answer 6

adhesions, hernias, neoplasms, etc

Question 7

Examples of intrinsic disease

Answer 7

congenital malrotation, atresia, stenosis, duplication, congenital bands; IBD, radiation, TB, traumatic, intussusception, volvulus

Question 8

Example of luminal abnormalities

Answer 8

bezoars, feces, foreign bodies

Question 9

Operations that are most likely to create adhesions that can cause bowel obstruction

Answer 9

Open operations of the lower abdomen such as appendectomy and colorectal and gynecologic procedures

Question 10

commonly affected part of volvulus

Answer 10

sigmoid

Question 11

True or false. It is rare for adhesions or hernias to obstruct the colon

Answer 11

True.

Question 12

Responsible for most cases of chronic volvulus

Answer 12

Cancer of ascending colon and rectum

Question 13

Other names of functional obstruction

Answer 13

ileus and pseudo obstruction

Question 14

Most common identified form of functional bowel obstruction

Answer 14

ileus that occurs after intraabdominal surgery

Question 15

Relatively rare where patient have chronic dysmotility due to abnormalities of their autonomic nervous system that may be inherited

Answer 15

Ogilvies syndrome

Question 16

Primary contributor to intestinal obstruction

Answer 16

swallowed air

Question 17

How early can epithelial necrosis can be identified in intestinal obstruction

Answer 17

Within 12 hours of obstruction

Question 18

What is the mechanism of dehydration in intestinal obstruction

Answer 18

loss of normal intestinal absorptive capacity as well as fluid accumulation in the gastric or intestinal wall and intraperitoneally

Question 19

What type of obstruction does nausea and vomiting occur

Answer 19

high grade distal obstruction

Question 20

How does intestinal obstruction lead to dyspnea and vascular instability

Answer 20

Intraperitoneal fluid increase the intraabdominal pressure enough to elevate the diaphragm inhibiting respiration and to impede systemic venous return leading to vascular instability

Question 21

Refers to when the proximal and distal openings of a given bowel segment are both occluded like due to a volvulus or a hernia

Answer 21

closed loop obstruction

Question 22

Most common precursor for strangulation

Answer 22

closed loop obstruction

Question 23

True or false. All closed loop obstruction leads to strangulation

Answer 23

False. Not every one

Question 24

At what diameter is the cecum most likely to perforate

Answer 24

Cecal diameter exceed 10-12 cm

Question 25

What type of patient will present with close loop obstruction early and warrant early intervention

Answer 25

patient with high grade distal obstruction competent ileocecal valuve and prone to close loop obstructon earlier than those with imcompetent ileocecal valves

Question 26

Cardinal signs of intestinal obstruction

Answer 26

colicky abdominal pain, abdominal distention, emesis and obstipation

Question 27

In intestinal obstruction which part will be dilated and which part will be collapse

Answer 27

Proximal to the obstruction there is bowel dilatation and the distal part is collapse

Question 28

Differentiate distal from proximal intestinal bowel obstruction

Answer 28

distal intestinal bowel obstruction greater distention, more discomfort, delayed feculent emesis when there is bacterial overgrowth; proximal intestinal bowel obstruction present with less abdominal distention but more pronounced vomiting

Question 29

Bowel sounds of early small bowel obstruction

Answer 29

high pitched, musical, tinkling bowel sounds

Question 30

Differential bowels sounds of intestinal obstruction versus ileus or pseudo obstruction

Answer 30

in intestinal obstruction there is high pitched tinkling bowel sounds in the beginning before becoming absent or hypoactive while in ileus it is hypoactive or absent bowel sounds right at the beginning in intestinal obstruction there is high pitched tinkling bowel sounds in the beginning before becoming absent or hypoactive while in ileus it is hypoactive or absent bowel sounds right at the beginning

Question 31

Typical presentation of patient with colonic volvulus

Answer 31

severe abdominal pain, vomiting, obstipation and asymmetrical abdominal distention and a tympanic mass may be evident

Question 32

classical findings in intestinal obstruction

Answer 32

staircasing pattern of dilated air and fluid filled small loops more than 2.5 cm in diameter with little or no air seen in the colon

Question 33

When can small bowel air fluid levels not be obvious on abdominal radiograph of intestinal obstruction

Answer 33

air fluid levels may not be obvious if the ileocecal valve is competent

Question 34

What is the sensitivity of CT scan in detecting bowel obstruction

Answer 34

About 95%; specificity of 96% and accuracy of more than 95%

Question 35

CT scan imaging of volvulus

Answer 35

birds beak or c-loop or whorl deformity on CT scan show where the twisting obstruct the lumen in volvulus

Question 36

Most specific early finding of bowel ischemia

Answer 36

altered bowel wall enhancement

Question 37

Late CT scan findings of bowel ischemia

Answer 37

mesenteric venous gas, pneumoperitonium and pneumatosis intestinalis

Question 38

True or false. Barium studies are part in the workup of intestinal obstruction for better visibility

Answer 38

False. Barium studies are contraindicated esp in patients with firm evidence of complete or high grade obstruction as it may develop into barium concretions causing additional source of blockage

Question 39

May be given to patients with ileus to accelerate gastrointestinal recovery

Answer 39

u opioid receptor antagonist such as alvimopan and mehtylnatrexone

Question 40

An acetylcholinesterase inhibitor that increase cholinergic activity and stimulate colonic motility in patient with Ogilvie's

Answer 40

neostigmine

Question 41

True or false. 60-80% of patients with mechanical bowel obstruction can be managed successfully with conservative measures

Answer 41

True.

Question 42

Done to decompress the stomach, minimize further distention and improve patient comfort

Answer 42

nasogastric tube suction

Question 43

Most common site of intestinal obstruction in patients with gallstone

Answer 43

ileum in 60% of patients

Question 44

How early can postoperative mechanical obstruction occurs

Answer 44

as early as the first 6 weeks of operation

Question 45

true or false. In postoperative bowel obstruction, the longer it tales for the obstructive symptoms to resolve after hospitalization, the more likely is the patient to require surgical intervention

Answer 45

True.